Pneumatic drill.



Patented Mar. l, i902.

No. 694,9sl.'

. Y .l. T. MGGRATH.

PNEUMAT'IC DRILL.

(Application Bled Nov. 24, 1900.)

(Na Model.)

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NITED STATES PATENT OFFICE.

JOHN T. 'MCGRATIL OF STRATFORD, CANADA. i

PNEUMATlC` DRILL.

SPECIFIGATION forming part of Letters Patent No. 694,981, dated March 1 1, 1902.

Application filed November Z4, 1900. Serial No. 37,668. (No model.)

To mit whom in' may concern..-

Be it known that I, Jenn T. MCG-RATE, of the city of Stratford, in the county of Perth, in the Province of Ontario, Canada, have in- Vented certain newand usefullmprovements in Pneumatic Drills, of which the following is a specification. Y

My invention relates to improveinentsfin pneumatic drills; and the object of the invention is to devise a pneumatic feed for the drill which will take the place of the present screw-feed and which may be regulated at a nicety, so as to regulate the speed of the' feed as maybe required, this depending, of course', upon the class of metal which is to be drilled; and it consists, essentially, of a casing having located therein a branch passage-way connected with the main passage-way, by which air is conveyed for the driving of the cylinders 'which rotate the drill, such branch passage-way leading into a supplemental cylindrical casing at the top of the main drivingcasing, in which is located a piston which is designed to be moved upwardly by the passage of the air through such branch passageway, such passage of the air and the parts being arranged and constructed in detail as hereinafter more particularly explained.

Figure 1 is a side elevation, mostly in sec.

tion, showing parts of the drill-driving casi ng towhich my invention relates. Fig. 2 is a sectional perspective detail of the main operating portions for controlling the branch passage-way. Fig. 3 is a sectional end view through the branch passage-way and main passage-way. 'Fig 4 is a perspective detail of the enlarged end of the main tube. Fig.- 5 is a detail of the top of the supplemental cylindrical casing. l

In the drawings like letters of reference indicate corresponding parts in each ligure.

A is the casing, and B the drill.

O is the cylindrical driving mechanism, which is of the common form used in pneumatic drills, such mechanism being located within a chamber D, as indicated.

E is a tube which extends into a circulairecess A in the upper portion of the casing A, whichis' shown in section. The tube E is secured in position by means of the screwnut e, which is internally threaded to llt in the corresponding thread in the recess A and internally threaded, so as to fit on the correspondingly-threaded end of the tube. A nurled sleeve E' is provided, which is suitably fastened in the tube E by means of the screw-pin e.

The tube E is provided With an enlarged end E2, in which is formed a small notch e2, communicating with the branch passage-way F, and enlarged notch e3, communicating with the extension e4 of the main passageway e5, formed by the tube, such extension passage-'way c4 extending into the chamber D and being designed to convey the air, so as Yto rotate the cylindrical driving mechanism C. It will be noticed that the small notch e2 is provided at the periphery with a laterally-extending notch e6. I also provide in the periphery of the enlargement E2 a longitudinally-extending notch el, which is designed to communicate with the oblique passage-way a, leading through the casing D, for a purpose which will hereinafter appear.

The passage-Way F leads, as will beseen in the drawings, to the bottom of a cylindrical chamber D to a point beneath the piston G, which is provided with an extension-sleeve g, Ywhich extends through the head A2 of the cylindrical chamber D. It will be noticed that dat sides g' are formed on the end of the sleeve g, and the sleeve is held from rotating by the ilatsided end ofv the sleeve g, extending into a corresponding hole in the head A2.

H is a screW-spindle,which is provided with the usual manipulating-wheel H. The screwspindle extends into a correspondingly inter-l 'nally threaded hole 'g2 in the sleeve g. The

bottom portion g3, however, of the hole g2 is not threaded, as lwill be seen.

Intermediate ofthe length of the passageway I provide a faucet or stop-cock I, which is operated by handles t', such faucet being .provided "with the usual cross-hole i?, and

when the handle is turned the position of such hole will control the supply or limit the supply, as desired, of the air through the branch passage-way F into the chamber D.

The main pressure of air is conducted through the passage-way of the tube e5 and the extension passage-way eAL to the main driving mechanism C, hereinbefore described. This pressure of air, however, is simply utilized for rotating the drill. By turning the sleeve e so that the notches e2 and e3 are vertical to each other and opposite their respective passage-Ways c* and F, it will be seen that the air will pass also into the branch passage-way F, and by turning the faucet I ever so little an upward movement will be imparted to the piston G, thereby imparting a down pressure to the drill, as of course the upper point of the spindle G is stationary, as is well understood in drills 0f this class. Vhen the piston G has been forced to the limit of its upward stroke, so as to give the hole its full depth, the drill may be ,given a still increased depth by manipulating the handles H', so as to lower the drill still farther, as may be required. It will thus be seen that I have in reality the advantages of a pneumatic feed as well as a hand-feed in one and the same drill. The exact rapidity7 of feed may of course be regulated by a faucet I. `When the piston G has been forced the limit of its stroke, the sleeve E may be turned so as to bring the notch eT opposite the oblique passage-way a, whereupon the supply of air to the drill will be shut oif and the air will escape from the feed, thus allowing of the piston Gto assume its normal position. Should, however, it be desired when the drill is being fed pneumatically to slacken the speed of rotation of the drill, this may be accomplished by giving the sleeve E a partial turn, so as to bring the tube E and lateral extension c of the passageway e around slightly,thereby allowing the air still to pass through the branch passage-way I1 to provide for the feed. The opening c3 is correspondingly moved circumferentially, so that the orifice leading to the extension passage-Way e4 is diminished as may be desired. Of course the form of the casing and the means for driving the drill may be of a different construction than that generally outlined in the drawings; but it will be linderstood that I can change the construction and position of my supplemental piston and cylinder, which is shown at the top in the present instance, to accommodate itself to any form of construction or drive of drills, and this, too, without departing from the spirit of my invention.

Vhat I claim as my invention isl. In combination,the casing,the drill-spindle and driving means therefor, an air-pipe for supplying compressed air to said driving means, a cylinder carried by said casing, a piston working therein carrying a feed-spindle and a branch conduit from said air-pipe to said cylinder, substantially as described.

2. In combination, the casing, a drill-spindle with driving means therefor located Within the casing, an air-pipe for supplying compressed air to operate said driving means, a cylinder axiallyin line with said drill-spindle and forming a part of said casing, an air-conduit from said air-pipe to said cylinder, and a feed-spindle adjustably connected to said piston, substantially as described.

3. The combination with the casing having suitable pneumatic driving means located therein and the air-tube leading thereto provided With an extension passage-way leading to the main driving means and a branch passage-way and a minor cylindrical chamber to which such passage-way leads, of the piston and sleeve thereof provided with fiat upper sides, the head of the cylinder having a corresponding recess to receive the end of the sleeve, the screw-spindle extending into the wheel and the operating-wheel for the same and means for controlling the supply of air through the branch passage-way as and for the purpose specied.

4. The combination With the casing and the driving means and the feeding means located therein and the branch passage-way and eX- tension passage-ways formed in the casing and leading to the respective chambers of the driving mechanism and the feeding means,of

a tube having an enlarged head and a small notch to connect with the branch passageway and an enlarged notch to connect With the extension passage way and means for controlling the supply of air through the branch passage-Way as and for the purpose specified.

5. The combination with the casing and the driving means and the feeding means located therein and the branch passage-Way and extension passage-Ways formed in the casing and leading to the respective chambers of the driving mechanism and the feeding means, of a tube having an enlarged head and a small notch to connect with the branch passage- Way and having a lateral circumferential extension and an enlarged notch to connect with the extension passage-Way and means for controlling the supply of air through the branch passage-way as and for the purpose specified.

6. The combination with the casin g and the driving means and the feeding means located therein and the branch passage-way and extension passage way formed in the casing and leading to the respective chambers of the driving mechanism and the feeding means, of a tube having an enlarged head and a small notch to connect with the branch passage- Way and having a lateral circumferential eX- tension and an enlarged notch to connect with the extension passage-Way, said head having a supplemental longitudinal notch and said casing having an oblique passage-Way with which the said notchis designed t-o be broughtinto communication and means for controlling the supply of air through the branch passage-Way as and for the purpose specified.

7 In a device of the class described, the

IOO

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combination with the driving means and the feeding means and the extension passage- Way and the branch passage-Way leading re-l speetively thereto, of the tube having 'an enlarged head with end notches as shown, such tube fitting in a. recess in the easing and the nut for securing such tube in position,V so as to permit of its turning as and for the purpose specified. o

J OHN T. MCGRATH.

Witnesses: y B/LPHELAN, .1.0. MAKINS. 

